Prefabricated, modular building panels generally are formed of a pair of spaced apart walls, surfaces, or skin sheets, having inserted therebetween some kind of insulating core material. In recent years, a variety of foamed polymers (e.g., polyurethane and polystyrene) have been used as the insulating core material for such modular building panels. Various problems, however, have been encountered in the design and structure of modular building panels. The industry has struggled to find ways to integrate, into a modular building panel, the combination of thermal insulation, mechanical strength desired for the panel, fire resistance and/or other desired properties.
There have been various prior art attempts to provide improved panels. For example, U.S. Pat. No. 4,641,469 issued to Wood teaches a modular panel made with polyurethane foam board or polystyrene foam board. Flanged rigidifying channels are inserted into the foam board by sliding them lengthwise into channels cut into, and extending across, the foam board. At the construction site, the board is attached to the building structural members by use of the rigidifying channels.
In U.S. Pat. No. 4,961,298 issued to Nogradi, "C-shaped" aluminum rigidifying channels are embedded into the foam board by transverse movement of the channels relative to the foam board, and are held to the board by adhesive. At the construction site, the board is glued to a substrate wall surface.
Both Wood and Nogradi teach using light-weight coatings on the board surfaces. Typical coatings are acrylic-based coatings or cementitious materials. Neither Wood nor Nogradi teach any reinforcing means extending between the two outer surfaces of the modular building panel. Accordingly, they are unable to provide any structural connection between the building structural members and the surfaces of the modular building panels which are disposed outwardly of the building. The panels of Wood and Nogradi lack the ability to secure heavy components, such as brick, on the outside surface of such modular panels to the structural members of the building, by connection through the elements of the modular panel. Accordingly, both the Wood and Nogradi panels lack mechanical strength. Neither do they offer a noncombustible insulating panel or protection from penetration of ballistic projectiles.
U.S. Pat. No. 4,837,999 issued to Stayner teaches a modular insulating panel made with a foam board core member, and having fiberglass-impregnated and/or filler-impregnated "C-shaped" or "H-shaped" thermoset resin pultrusions on opposing edges of the foam boards and extending between the inner and outer surfaces of the modular panel. The pultrusions in Stayner can perhaps provide a reinforcing connection between the building structural members and the outer surface of the building modular panels, while maintaining a reasonable thermal barrier between inner and outer surfaces of the modular panels at the pultrusions. But the polymer resin-based pultrusions inherently comprise a continuous-phase embedding polymeric material which receives the reinforcing fiberglass and/or any filler used. Accordingly, while the pultrusion may have a lower fire spread rate, it can contribute fuel to the burning of a fire. Of even greater concern, the polymer-based pultrusion can melt. Stayner makes no claim that his pultrusion is noncombustible or nonmelting. Rather, he suggests using noncombustible mineral wool for some or all of the core member of the modular panel, in order to reduce or eliminate combustibility of the core member. His only suggestion that offers elimination of the combustibility of the pultrusions is to replace the pultrusions with corresponding members made with metal. Stayner admits that such metal members would compromise the insulating value of the modular panels. He does not address the susceptibility of his polymer to melt. Stayner offers no mechanical reinforcing means and no bullet-proofing.
Thus, a persistent and vexatious problem in the art is the lack of a modular panel having the combination of good thermal insulation and mechanical properties, as well as maintenance of structural integrity during fire conditions; namely noncombustible and nonmelting properties, preferably including reinforcing connections between the building structural frame and the outer surface of the outer wall of the building. Neither does the art teach or suggest a modular building panel offering substantial protection from penetration of ballistic projectiles. Despite recognition of these design problems, proper solutions to these problems have not been demonstrated in the art.